The mysterious wet bolt
The friends we travel with just had a shackle bolt fail on their fifth wheel trailer and it could have been pretty catastrophic. The mobile repair guy installed a new bolt and shackle and told us we both should look into “wet bolts” What are these? — Don
Shackles and bolts attach the leaf springs of a trailer to the frame. Shackles are short metal plates with a bolt hole at each end that connects one end of the leaf spring either to an equalizer (tandem axles) or the frame. The bolts and shackle work together to allow a pivoting action so the leaf spring can change length as it compresses and rebounds. Leaf spring eyes are larger in diameter than the bolts, allowing a bushing to be used to mitigate friction. Original equipment bushings are typically nylon. In time the bushing wears, the holes in the shackles can elongate and the bolts may wear thinner and potentially fail.
Wet bolts are shackle bolts with a small internal passage and a Zerk fitting threaded into the bolt head. A bronze bushing is used instead of the nylon, and the assembly can be lubricated using a grease gun. This is a big improvement in friction reduction, and long-lasting, as long as the bolt is of high quality. If renewing these parts, it’s not a bad idea to upgrade the shackles to thicker/beefier versions and remember to apply lubricant periodically. I would go with parts sold by a company such as E-trailer rather than looking for something inexpensive on Amazon. The car I recently purchased makes me crazy because the gas gauge reads funny. If you fill it up you can drive about 200 miles before it reaches 1/2. Then, the last half of the tank only lasts about 130 miles and seems to go to empty quickly from 1/4 tank which has scared me a few times. Is there a fix for this? — Amy K.
Fuel gauges have to be the most non-linear of all instruments, with some worse than others! I think it has to do with the odd tank shapes employed to fit beneath the vehicle and less than stellar geometry in the tank sending unit arm-swing. Assuming your gauge reads full after a fill-up, it requires perhaps 80 percent of the tank’s rated capacity to fill up when near-empty, and doesn’t make any sudden drop-off movements, the gauge is probably behaving as designed. My Chevy Tahoe has a torpedo shaped tank that gives widely differing fuel gauge readings during up or down hill driving in addition to behaving similarly to yours. I live with it and consider 1/4 to be my empty! What can be done to get rid of the stinky smell coming from my air conditioning? — Jessica
The unpleasant odor you have encountered is fungi growing on the air conditioning evaporator and possibly within the evaporator case. These are air conditioning parts located behind/under the instrument panel. Over the counter and professional treatments administered through the inlet duct at the base of the windshield can be effective. Switching from recirculation mode to outside air during the final few miles of each drive can help dry out the evaporator and case to reduce future fungi build up.
Brad Bergholdt is an automotive technology instructor at Evergreen Valley College in San Jose, California. Readers may send him email at bradbergholdt@gmail.com; he cannot make personal replies.